<!-- 
 
  求45,78,96,86最大值?

-->
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<!-- 
    
-->

<body>
    <script>
        var num1 = 45, num2 = 78, num3 = 96, num4 = 86, max = num1
        if (max < num2) {
            max = num2
        }
        if (max < num3) {
            max = num3
        }
        if (max < num4) {
            max = num4
        }
        console.log(max)
    </script>
</body>

</html>